Assistant Professor University of Utah Health Salt Lake City, Utah, United States
Objective: It is common to await spontaneous labor in individuals undertaking a trial of labor after cesarean (TOLAC) over concern of uterine rupture and its associated harms. We evaluated whether this concern is warranted.
Study Design: Secondary analysis of a multicenter cohort of patients delivering on randomly selected days at 17 U.S. hospitals (2019-20). Data were manually abstracted from the medical record by trained staff. Term individuals with a prior cesarean delivery (CD) were included while those with a contraindication to TOLAC, planned repeat CD, multifetal gestation, stillbirth, or fetal anomaly were excluded. The primary outcome was vaginal birth after cesarean (VBAC). Secondary outcomes included uterine rupture, maternal morbidity, neonatal morbidity, and NICU admission. Multivariable modeling estimated the association between induction compared with expectant management and outcomes by gestational week. Adjusted Desirability Of Outcome Ranking (DOOR) analyses calculated the probability that induction leads to more desirable dyadic (paired maternal-neonatal) outcomes. The ordinal DOOR outcome ranged from VBAC without uterine rupture or morbidity (most desirable) to CD with uterine rupture and maternal and neonatal morbidity (least desirable).
Results: Of the 935 individuals included, mean maternal age was 31 years (± 5), median body mass index 31.8 kg/m2 (interquartile range 27.7-36.7), and 89% had one prior CD. In adjusted multivariable models, there was no association between induction and odds of VBAC in week 37, 38 or 40; in week 39, induction was associated with increased odds of VBAC (Table). Induction and expectant management had similar odds of maternal morbidity at all weeks, while induction was associated with neonatal morbidity and NICU admission only at week 37. In DOOR analyses, induction in week 39 resulted in a higher probability of a desirable outcome for the dyad (adjusted DOOR probability 55%, 95% CI 51-59%; Figure).
Conclusion: For those undertaking TOLAC, induction compared with expectant management in gestational week 39 optimized outcomes for the maternal-neonatal dyad.
.jpg "Ann M. Bruno, MD MS (she/her/hers) photo")
